Frequently Asked Questions

Q: What are the HPC facilities available at IUCAA?
  To see available HPC facilities at IUCAA click here
 
Q: How do I get a cluster account?
  Faculties and student can directly request for cluster account where as, visitors and associates request should come through their collaborator faculty. To request an cluster account click here
 
Q: How many cores I can use?
  It's depend on the total number of the available cores. You can refer cluster policies for more details.
 
Q: How do I login to a cluster?
  You can login to cluster using ssh command.

Syntax:- ssh -X username@clustername or cluster IP address.

For example, You can login to Peruseus using following command,

ssh -X username@perseus.ac.iucaa.ernet in

or

ssh -X username@192.168.11.245

Please note that, from a Windows machine use PuTTY and set the remote server as perseus.ac.iucaa.ernet.in and username as your your_id and achieve the same

 
Q: Which compilers and application software are available on Perseus?
  Please refer to compiler and application softwares in perseus
 
Q: How do I setup a MPI environment on Perseus?
  To Intel MPI add below line to your .bashrc file,

source /opt/software/intel/icsxe/2013.0.028/ictvars.sh

To use Platform MPI add below line to your .bashrc file

source /opt/platform_mpi/SetPMPIPath.sh

 
Q: Which cluster management tool is installed on Persus?
  Perseus uses Platform Load Sharing Facility (LSF) for cluster management.
 
Q: How do I run my computational job?
 

step 1 : you need to setup your working environment in order to fully utilize the system (refer FAQ 6).

step 2 : check what resources (e.g. system and software, hardware) are available and whether these resources are enough for you to run your job.

step 3 : write a lsf script, below is example lsf script to run mpi job a.out with 4 processes

#!/bin/bash
#BSUB -L /bin/bash ## Specify Shell
#BSUB -J myjob ## Specify Job Name
#BSUB -q normal ## Specify Queue Name
#BSUB -o out.dat ## Specify Output File
#BSUB -e err.dat ## Specify Error File
#BSUB -n 4 ## Specify Number of Cores
mpirun -np 4 ./a.out    

click here to download the above script

 
Q: How do I check status of my job?
  A job can be in PENDING, RUNNING, SUSPENDED or EXIT state. You can use bjobs command to get status of your job,

Syntax:- bjobs <job id>

 
Q: How do I get list of all running, pending and existed jobs?
  You can use bjobs command to get list of all type jobs. By default, displays information about your own pending, running and suspended jobs.

Syntax:- bjobs

-a Display list of the jobs in all states including finished and recently finished job with in an specified clean period
-d Display list of the jobs which are finished recently, with in clean period.
-p Display list of the jobs which are in pending state.
-r Display list of the jobs which are in running state.
-s Display list of the jobs which are in suspended state.
-x Displays list of jobs that have trigger exception.
-WF Displays estimated finish time for the running or pending jobs.
-WL Displays running time of the job.
 
Q: How do I change resources of my job when it is running?
  bmod command can be used to change resources of a running job
 
Q: How do I kill my job?
  bkill command can be used to kill running/pending job,

Syntax:- bkill <job id>

 
Q: How do I suspend my job?
  bstop command can be used to suspend running/pending job,

Syntax:- bstop <job id>

 
Q: How do I resume a job suspended by bstop?
  bresume command can be used to resume job suspended by bstop,

Syntax:- bresume

 
Q: How do I get list of available queues?
  bqueues command can be used to get list of available queues,

Syntax:- bqueues

 
Q: How do I get list of free and used nodes?
  sinfo command gives gives list used and idal nodes,

Syntax:- sinfo

 
Q: How I can change my password on cluster?
  You can use yppasswd command to change your cluster account password.

Syntax:- yppasswd